presidential debate started with a hand shake and a smile between president obama and his republican challenger, mitt romney. then, it quickly focused on the economy. >> 5 million jobs in the private sector created. the auto industry's come roaring back. and housing has begun to rise. >> i know what it takes to get small business growing again, to hire people. >> reporter: romney was aggressive most of the night. but his comments about the 47% had taken a toll on his campaign. the president never brought up those comments. and romney tried to move past them. >> under the president's policies, middle-income americans have been buried. they're just being crushed. i will not, under any circumstances, raise taxes on middle-income families. >> reporter: the president challenged his rival, saying that romney cannot keep his goal of cutting taxes and not add to the deficit without hurting the middle-class. >> now, five weeks before the election, he's saying his big, bold idea is never mind. >> reporter: other topics included medicare reform and the president's health care reform law. while there wasn'